Mathematical modeling of biofuel synthesis and storage

summary

Preface

CHAPTER 1: MATHEMATICAL MODELING APPLIED TO BIODIESEL SYNTHESIS: QUATERNARY MIXTURES

CHAPTER 2: OPTIMIZATION OF ALCOHOLIC FERMENTATION OF BUTIÁ AND JERIVÁ AQUEOUS EXTRACTS: APPLICATION OF RESPONSE SURFACE METHODOLOGY TO THE VARIABLE PROCESS

CHAPTER 3: MATHEMATICAL MODELING OF THE RELATIVE PROTECTION FACTOR OF NATURAL ANTIOXIDANTS IN COMMERCIAL BIODIESEL

CHAPTER 4: ANALYSIS OF THE BEHAVIOR OF SYNTHETIC ANTIOXIDANTS IN COMMERCIAL BIODIESEL: APPLICATION OF SELF ORGANIZING MAPS

CHAPTER 5: THERMODYNAMIC PARAMETERS EVALUATION OF THE BIODIESEL OXIDATION REACTION IN CONTACT WITH METALLIC ALLOYS

CHAPTER 6: MIXTURE OPTIMIZATION OF HETEROGENEOUS METAL OXIDE CATALYSTS FOR BIODIESEL PRODUCTION

CHAPTER 7: INFLUENCE OF SENNA LEAVES, BLACKBERRIES AND HIBISCUS FLOWERS EXTRACTS IN THE THERMODYNAMIC PARAMETERS OF THE BIODIESEL OXIDATION REACTION

CHAPTER 8: CATALYTIC EFFECT MODELLING OF DIFFERENT TRANSITION METAL IONS IN THE COMMERCIAL BIODIESEL OXIDATION REACTION

Preface

Science and technology are in increasing development. One of the most important and interesting aspects of scientific research is the search for the optimal solution. In this context, systems and processes used in the manufacturing industries are always looking for the best product with the highest yield and process optimization. Therefore, the search for more efficient means for processing or products formulation can be streamlined using mathematical modeling.

Currently, the development of mathematical models and new numerical algorithms to solve optimization problems using conventional and unconventional statistical methodologies and the easy access to computers has enabled scientists and technologists to rapidly develop new products, improve quality and minimize manufacturing costs.

To increase efficiency in the search for the best product, empirical factorial plans have been widely used in the modeling of systems to be optimized, mainly in exploratory analysis of the behavior of the variables involved. Among these experimental designs, the mixture design, the response surface methodology and, more recently, the use of artificial neural networks are highlighted.

This book brings together some examples of how the simplex-centroid mixture design, response surface and artificial neural networks of the self-organizing maps type can be applied in obtaining, formulating, conserving (using extracts with antioxidant properties) and storage of biofuels such as biodiesel and fuel alcohol. The research was carried out at the Fuel Research and Analysis Laboratory, at the Exact Sciences Center (CCE- Centro de Ciências Exatas) of the State University of Londrina (UEL- Universidade Estadual de Londrina).

Gathering knowledge acquired over the years through consultancies, lectures, analyzes, our research group has solid experience in the modeling and optimization area of systems and processes used in chemical and related industries.

In this book, readers will find practical details that illustrate the application of mathematical modeling as well as the statistical analysis of the data obtained, encouraging the use of the tools presented in future research involving distinct areas in the biofuels obtention and storage.

Karina Benassi Angilelli

Ana Carolina Gomes Mantovani

Letícia Thaís Chendynski

Londrina, 2021

CHAPTER 1

MATHEMATICAL MODELING APPLIED TO BIODIESEL SYNTHESIS: QUATERNARY MIXTURES

LETÍCIA THAÍS CHENDYNSKIa; ANA CAROLINA GOMES MANTOVANIb; KARINA BENASSI ANGILELLIc

a Federal Institute of Parana, Campus Palmas, Bento Munhoz da Rocha Neto Avenue, Zip Code: 85555-000, Palmas PR, Brazil

b State University of Londrina, Physics Department, Electron Paramagnetic Resonance Laboratory, PO Box: 10.011, Zip Code: 86057-970, Londrina, Paraná, Brazil.

c State University of Londrina, Chemistry Department, Fuel Research and Analysis Laboratory, PO Box: 10.011, Zip Code: 86057-970, Londrina, Paraná, Brazil.

ABSTRACT

The low cost and high availability of animal fat generate industrial interest in its use, together with soybean oil for biodiesel production, reducing costs and maximizing profit. The experiment design is a technology applied to achieve a product of excellence, optimizing systems and processes, reducing costs, and solving any manufacturing problems. This work aimed to apply the experimental design to obtain B100 biodiesel from a blend of soybean oil, poultry fat, beef tallow, and pig fat to obtain predictive equations that can model the transesterification reaction yield and oxidative stability, using sodium hydroxide and sodium methoxide as catalysts. The presence of animal fat in the formulations is a factor of interest, although not presenting good isolated results such as low oxidative stability (pig fat) and high fog and flow points (beef tallow), they present good yield, and can be used as a partial substitute of soybean oil in mixtures. The joint optimization provided a mixture of 21% soybean oil, 21% beef tallow and 58% poultry fat when using NaOH and 60% of beef tallow and 40% of poultry fat when using NaOCH3.

Keywords: Experimental design; simplex-centroid; optimization

INTRODUCTION

There is an interest in the development of technologies that make it possible to use renewable energy sources to replace fossil fuels, total or partially. The world community seeks a sustainable development with lower environmental impact and economic viability (Chendynski et al., 2016), since most of the energy consumed comes from fossil, non-renewable and polluting sources (Osawa et al., 2016).

One of the renewable energies that has been the focus of many studies are biofuels. They can be defined as fuels derived from renewable raw material. The most commonly used types of biofuels are: biodiesel, bioethanol and biogas, which are mainly obtained from vegetable oils, seeds and lignocellulosic materials, with bioethanol as a substitute for gasoline and biodiesel as an alternative to diesel (Jishnu and Pai, 2018).

According to the Brazilian National Agency of Petroleum, Natural Gas and Biofuels (ANP) biodiesel is a biofuel produced from renewable biomass for use in compression-ignition internal combustion engines or for the generation of another type of energy, which may partially or totally replace fossil fuels. In early 2005, the law 11.097 was published, introducing the biodiesel in the Brazilian energy matrix. From November 2014, with the new legislation, biodiesel could be added at a rate of 7%, not causing problems to the engine. Nowadays the percentage added achieved 11% (Brasil, 2016, 2018).

With the greater commercialization of biodiesel, a greater demand for biodiesel quality control is required. The ANP predicts that oxidative stability should be at least 12 h at 110 °C for biodiesel. This parameter depends on the raw material of the oil used in the biodiesel production (Brasil, 2019).

The raw materials used for the biodiesel production can include vegetable oils such as: soybean, sunflower, palm, and other non-edible oils, as Mahua, Neem, Karanja, Jatropha; animal fats such as: tallow, lard and poultry fat and residual oil, sources of triglycerides that form biodiesel after synthesis. New sources as algae are considered the third generation of biofuel (Chendynski et al., 2016).

Biodiesel from vegetable or animal fats has less oxidation stability compared to diesel, having higher levels of unsaturated esters, particularly polyunsaturated, which can be oxidized, causing the formation of compounds as acids, aldehydes, esters, ketones, alcohols and peroxides De Carvalho et al. (2016) and Sorate; Bhale (2015).

Biodiesel is a practical example of the biomass use for energy production, presenting several advantages over petroleum diesel as: minimal toxicity, and being from renewable and biodegradable sources (Angilelli et al., 2017; Osawa et al., 2016). The different raw materials for the biodiesel synthesis have different properties and/or characteristics in the final product, for example, oil with a high content of saturated fatty acids can provide greater oxidative stability and a high number of cetane. However, it solidifies at higher temperatures when compared to a biodiesel produced by a high content of unsaturated fatty acids (Chendynski et al., 2016; Sorate; Bhale 2015).

In the synthesis of a biodiesel, the reaction yield, oxidative stability, and legislated parameters are considered, so it is necessary to use experiments that consider these dependent variables. The experimentation aims to better understand the process and thus improve operating conditions (Rizwanul Fattah et al., 2014; Yaakob et al., 2014).

Experimental design is based on statistics, mainly for the efficient design of experiments and their possible interferences. The experimental design is a technology that can be applied to achieve an excellent product, optimizing systems and processes, reducing costs and solving eventual manufacturing problems (Chendynski et al., 2016; Galvan et al., 2020).

The equation for simplex-centroid mixture design is based on matrix calculations:

η=Xβ (Equation 1)

η corresponds to a vector n x l for the answer and X corresponds to an n x p matrix of independent variables, Y the vector response and p x 1 for the vector (β) of the parameters. The calculation of the slope (b) of the response matrix is performed by:

b=[X’X]-1X’Y (Equation 2)

Chemometrics research can be grouped into three main areas: design and optimization of experiments, pattern recognition (methods of exploratory analysis and classification) and multivariate calibration. A planned experiment consists of a series of tests, in which purposeful changes are made to the input variables of a process, to observe and identify corresponding changes in the output response. It is possible to determine which variables are most influential in the results, assigning values to the influential variables to optimize the results or to minimize the results variability, or to minimize the influence of uncontrollable variables. When there are several factors of interest in an experiment, a factorial design can be applied. In such experiments, the factors vary together. Specifically, through a factorial experiment, all possible combinations of factor levels are investigated (Chendynski et al., 2016; Kimura et al., 2019).

Chendynski et al., (2020) evaluated the extracts efficiency of bacuri (Platonia insignis), araçá (Psidium cattleianum) and rosemary (Rosmarinus officinalis) in biodiesel with simplex-centroid mixture design. The research aimed to apply the experimental design to obtain B100 biodiesel from a mixture of soybean oil, lard, tallow, and poultry fat, to obtain predictive equations that can